Bag making machine



y 1945. R. c. HURREY BAG.M \KING MACHINE s Sheets-SHeet 1 Filed July 25, 1940 INVENTOR y R. c. HURREY 2,376,697

A BAG MAKING MACHINE Filed July 25, 1940 .I Sheets-Sheet 2 INVENTOR Ross C flue/Q57 ATTO R N EY May 22, 1945. R c HURREY 2,376,697

BAG:MAKING MACHINE Filed July 25, 1940 3 Sheets-Sheet 3 INVENTOR w q A 05: 6? flmkfr ATTORNEY L Patented May 22, 1945 BAG MAKING MACHINE Ross C. Hurray, New York, N. Y., assignor to Bagpak, Inc., New York,N. Y., a corporation of Delaware Application July'25, 1940,'Serial No. 347,367

3 Claims.

This invention relates to new and useful improvements in bag making machines, and particularly seeks to provide a'cylinder-for .the bottom fo'rming mechanism which includes novel front and back clamps designed to eliminate displacement of adhesive during the fold scoring operations.

Heretofore, in the folding of bag bottoms through the use of cylinder type folding mechanisms, much difliculty has been encountered in forming a sift-proof bag. Such difflculties have arisen mainly due to a tendency of the adhesive employed to be either actually displaced or forced into the paper during the fold scoring operations as the result of the strong wiping action set up by the tucker blades when they are backed up across their full width by a solid clamp and by pressure applied to the tucks by the clamp. Through the use of this invention the above mentioned difi'iculties are overcome, and it is now possible to obtain a properly-sealed bag bottom that is sift-proof.

Therefore an object of this invention is to provide the cylinder of a bottom folding machine with means for relieving the pressure of the bag tube against the tucker blades over those areas tion of the first step in forming the bottom of a bag of the automatic opening or ABC type;

Fig. 3 is a view similar to Fig. 2, but showing a second state in the formation of a bottom;

Fig. 4 is a view similar to Figs. 2 and 3, but showing the manner in which the bag tube is separated as the fundamental stage in forming the bottom of the bag;

Fig. 5 is a view similar to Fig. 4 showing the manner in which the tube is further opened and also the manner in which the side wall carried by the scoring wheel is removed therefrom;

Fig. 6 shows the paste applying stage in which the paste is applied in the manner indicated in Fig. 7 prior to the time at which the flaps of the bottom are tucked into the clamps so that paste will be provided in the tucks;

of the tube that are covered with adhesive to thereby minimize displacement or removal of adhesive from the tube and thus assure the formation of a sift-proof bag bottom.

Another object of the invention is to provide a device of the character stated in which the tube engaging surfaces of one side of the respective front and rear cylinder-carried clamps are provided with recesses of a width corresponding to or greater than the total width of the applied adhesive.

Another object of the invention is to provide a device of the character stated in which removal or displacement of adhesive from the tube due to pressure of the clamps is substantially avoided by providing voids in the tube-engaging surfaces of clamp faces which correspond in location and width to theposition and width of the adhesive applied to the tube.

With these and other objects in 'view, the nature of which will become more apparent, the invention willbe more fully understood by reference to the drawings, the accompanying detailed description, and the appended claims.

In the drawings:

Fig. 1 is a view in side elevation of the bottom forming cylinder of a bag making machine;

;Fig. 2 is a fragmentary view partially in sec- Fig. 7 is a plan view of the bag formed by the cylinder machine after paste has been applied and prior to the time that the front and rear flaps have been folded into position;

Fig. 8 is a view showing the manner in which the first tucker blade forces the outside flap into the front clamp thereby forming the score line about which the said flap is folded;

Fig. 9 is a view corresponding to Fig. 10 but showing the manner in which the score line demarking the inside flap operates to tuck a portion thereof into the bag clamp; and

Fig. 10 is a sectional view taken along the lines II], II] of Fig. 8 indicating the manner in which the bag clamp is relieved so as not to exert pressure against the line of paste positioned along the overlapped portion of the said flaps of the bottom which are moved into position by former plates which are located prior to the paste roll.

Referring now to the drawings in which like numerals indicate like parts and more particularly to Fig. 1, there is shown the cylinder portion of a bag making machine. As is well known in the art a web of material is formed into a tube, slit to provide the inside and outside flaps 20 and 2|, respectively, cut off into bag lengths at the end of the slits formed by the cylinder mechanism and thereafter passed between bottom and top score rolls 22 and 23, respectively, where the formation of the bottom of the bag commences.

Referring now to Figs. 2 and 3 there is shown the initial stagesof the bag formation. The-top score roll is provided with a score pin 24 which pierces that portion of the tube forming the inside flap 20. The top score roll is further provided with two score blades 25 and 26 which for purposes of description will be referred to respectively as first and second score blades. The bottom score roll 22 is provided with a pair of indentations 21 and 28 which mate respectively with the first and second score blades. Continued rotation of the top and bottom score rolls by any suitable mechanism removes the bag tube from operative contact with the bottom score roll and swings the tube into such position with respect the formation of only one bag bottom has been Y shown.

Continued rotation of the cylinder and the top and bottom score rolls will bring the gripper into operative contact with that portion of the tube which will form the outside flap of the bottom. The tube is designated by the numeral 30. Since the inside flap of the bottom is secured to the top score roll by the score pin 24 a gradual separation of the inside and outside flaps will occur until the bottom has been opened up to its full extent. In order to facilitate the formation of a substantially square bottom the cylinder is provided with a cylinder finger 3! which, mating with a corresponding finger 32 on the top score wheel, serves to hold the bottom in a square position. Continued rotation of the cylinder and the top score roll brings the outer edge of the inner and it will be noted that they are formed by forcing the flaps into front and rear clamps 4t and 41, respectively. Since, however, it is desired to insure the formation of a siftproof bottom, too much pressure along the paste bars 36, 31 and 8! and along said score lines 44 and 45, will in many cases force the paste out of thqtucks later to be formed so that leakage or sifting will occur along said some lines within the area of the overlapped portions of the sidewalls. It may also happen that too much pressure applied over the areas indicated will effect an undesirable impregnation of the paste into the fibers of the paper, thus killing" the paste. In order to prevent this removal, or killing of the paste, the clamps are relieved so that no pressure will be applied to the paste bars 34, 31 and 38 along the score lines 44 and 45. This is accomplished by cutting away each of the clamps 48 and 41 to flap into contact with a score dofier 33 which removes the said flap from the score wheel permitting it to be carried with the cylinder.

The tube is now in a position to contact with a pair of former blades 34 and 35 which fold over the sidewalls of the bottom. Since it is an object of the invention to provide a tight bottom the sidewalls are so folded as to rest in superimposed relation after having been operated upon by the former blades. It will be noted that in order to accomplish this result one of the former blades is positioned higher than the other and that sidewall which is to underlie the other sidewall contacts with the lower or leading former blade so that it is moved into flat position prior to the folding of the other sidewall.

The next stepin the formation of the bottom is to apply the paste bars 36, 31 and 38 on the bottom of the bag and further to apply the paste bar 39 on the inner flap and the paste bars 40 on the outer flap. This is clearly shown in Fig. 7 to which reference is hereby made. The paste is applied by means of a paste wheel 4| having a paste sector 42 so arranged on the periphery of the wheel as to come into contact with each bag bottom in timed relation. Although details of the paste sector have not been shown, obviously they are provided withribs corresponding to the contour of the paste bar applied to the bottom and bottom forming flaps. The paste sector receives its paste from the paste pan 43 in the well known manner. The paste is applied to the bag bottom prior to the formation of the score lines 44 and 45 in order to permit paste in the area of the paste bars to be forced into the tucks when the inside and outside flaps are folded therearound in order to complete the bottom forming operation.

Referring now to Figs. 8 and 9 there i shown the manner in which these score lines are formed form a slot or recess 48 as indicated in Fig. 10. Of course it will be readily apparent that both faces of each clamp may be slotted to provide a complete void over the area to which the paste bars are applied, or the form of the clamp jaws may be differently designed to provide spaced pairs of opposed clamping fingers that will serve effectively as clamps but which will also avoid applying pressure to the areas of the tube covered by the paste bars.

Referring now specifically to Figs. 8 and 9 in order to describe the operation of the tuck-forming mechanism it will be noted that the first tucker blade 5| mounted for rotation on the tucker roll 50 forces the bag tube into engagement with the front clamp 46 thereby forming the score line 44 about which the front flap 2| is folded in order to complete the bottom forming operation. As will be appreciated by those skilled in the art the necessary movement of the clamp is accomplished by a well known cam actuated means. Continued rotation of the cylinder and the tucker roll brings the second tucker blade 52 into contact with the rear portion of the partially formed the rear or inside flap is folded in order to com- I plete the bottoming operation. Simultaneously with the forcing of the rear portion of the bottom into the back clamp the gripper 29 releases the outside flap 2| and permits it to move out of contact with the wall of the cylinder.

Since the invention resides primarily in the formation of a siftproof bottom and in means for preventing the removal or displacement of paste along the superimposed portions of the side walls of the bag bottom, further description of the folding of the flaps into operative position is believed to be unnecessary. However, by reference to Fig. 1 it will be noted that after the tucking operation there is provided a folding bar chain trained around folding bar sprockets 53 and driven by any suitable means. The folding bar chain carries a folding bar 54 which swings into operation after the outside flap has moved to a position. to bring the said folding bar into contact with the inside flap to fold the same about the score line 45 and press it against the adhesive bars 35-39 to adhesively secure it to the folded down sidewalls. In order to accomplish this it is obvious that the folding bar is moving at a speed greater than the peripheral speed of the cylinder. Continued rotation of the cylinder brings the outside flap into contact with a folding shoe which is positioned so as not to be in the way of the folding bar and by pressure the outside flap is secured against the bottom and the inside flap. The outside flap fold 55 is indicated in dotted line outlines in Fig. 1. A bag now being completed passes between the cylinder and the delivery roll and by means of the doifer 56 is removed from the cylinder.

Many of the details of the operation of a bag making machine have not been shown since they form no part of the present invention. The method of tubing, slitting and cuttinga web of bag making material is well known and conventional in the art, as is likewise the detail operation of the flap folding mechanism just described. The first stages in the bag making operations have been omitted and the last stages in the formation of the bottom have been shown very schematically. The important phases of the invention. namely the scoring and tucking of the bag flaps, have been described in detail and it will be appreciated by those skilled in the art that it is impossible with the present mechanism to remove, displace, or kill" the paste along the superim-. posed edges of the sidewalls of the bottom. Hence at all times an absolutely siftproof bottom will be formed, and sifting tendencies at the weakest points in the formation of prior known siftproof bottoms have been corrected. Many changes in mechanical details will of course be readily available to those skilled in the art and the particular formation of the tuck folding and clamping means will be modified depending upon the particular type of bag making machine to which it is desired to apply the invention. Accordingly the invention is not to be limited except in the scope of the appended claims which are to be broadly construed.

I claim:

1. In a bagmaking machine including bottom forming mechanism having a cylinder adapted to releasably support a blank for bottom folding operations. means associated with said cylinder for applying adhesive to said blank, and means for transversely scoring said blank after the adhesive has been applied to form tucks therein;

the combination of means carried by said cylinder and adapted to be brought. into cooperative relation to said tuck forming means for receiving and gripping the tucks thus formed and including pairs of opposed jaws openable to receive a tuck and closable to grip a tuck, the gripping face of at least one of said jaws being discontinuous through a portion generally corresponding to the width of said adhesive whereby application of gripping pressure to those portions of the tuck containing adhesive will be substantially avoided.

2. -In a bag making machine including bottom forming mechanism having a cylinder adapted to releasably support a blank for bottom folding operations, means associated with said cylinder for applying adhesive to said blank, and'rneans for transversely scoring said blank after the adhesive has been applied to form tucks therein; the combination of means carried by said cylinder and adapted to be brought into cooperative relation to said tuck forming means for receiving and gripping the tucks thus formed and including pairs of opposed jaws openabie to receive a tuck and closable to grip a tuck, the faces of said jaws being provided with opposed discontinuous portions generally corresponding to the width of said adhesive wherebycsaid jaws will be incapable of exerting gripping pressure to those portions of the tuck containing adhesive.

3. In a bag making machine including bottom forming mechanism having a cylinder adapted to releasably support a blank for bottom folding operations, means associated with said cylinder for applying adhesive to said blank, and means for transversely scoring said blank after the adhesive has been applied to form'tucks therein; the combination of means carried by said cylinder and effective to grip the tucks thus formed only at places disposed beyond the defined limits of the applied adhesive whereby the application of gripping pressure to those portions of the tucks containing adhesive will be substantially avoided.

ROSS C. HURREY. 

